The herein invention is an improvement on the co-pending application of John A. Gaylord, Ser. No. 695,077 filed June 11, 1976, now U.S. Pat. No. 4,051,743.
The primary object of the invention is to provide a device of simple structure which can be easily manufactured and into which a belt can be quickly threaded and thereafter the belt can be adjusted with the minimum effort for clamping the belt in adjusted position or releasing the risers to permit adjustment, and wherein inadvertent release of the cam by body movement is obviated.